Microfluidic LAL-reactive substances testing method and apparatus

Abstract

A microfluidic testing cartridge for testing LAL-reactive substances in fluid samples is provided. The cartridge may include at least two (2) testing modules, wherein each testing module includes at least one inlet port for receiving one of the fluid samples, and at least four (4) testing channels in fluid communication with the inlet port. Each of the testing channels may include a metering portion for metering an aliquot of the fluid sample, an analyzing portion, and a mixing portion, wherein a valve is positioned between the metering portion and the analyzing portion to selectively fluidly separate the metering portion from the analyzing portion. The cartridge is insertable into an optical reader which performs optical measurements of the fluid sample within each testing channel during a testing process.

What is claimed is: 
     
       1. A microfluidic cartridge for testing fluid samples comprising at least two (2) testing modules, wherein:
 each testing module includes at least one inlet port for receiving one of said fluid samples, and at least four (4) testing channels in fluid communication with said inlet port; 
 each of said testing channels includes a metering portion for metering an aliquot of said fluid sample, an analyzing portion, and a mixing portion, said metering portion fluidly communicates with said analyzing portion, and said analyzing portion fluidly communicates with said mixing portion, 
 wherein a valve is positioned between said metering portion and said analyzing portion to selectively fluidly separate said metering portion from said analyzing portion; and wherein: 
 each testing module has at least one testing channel with at least one reagent isolated therein, said reagent comprising a  Limulus amebocyte lysate  (LAL)-reactive substance. 
 
     
     
       2. The microfluidic cartridge of  claim 1 , wherein at least one testing module is a calibration module comprising at least eight (8) testing channels and wherein: at least two (2) of said testing channels have no LAL-reactive substance therein; at least two (2) of said testing channels have a first amount of a LAL reactive substance isolated therein; at least two (2) of said testing channels have a second amount of a LAL reactive substance isolated therein; and at least two (2) of said testing channels have a third amount of a LAL reactive substance isolated therein. 
     
     
       3. The microfluidic cartridge of  claim 1 , wherein at least one testing module is a sample measurement module comprising at least four (4) testing channels and wherein; at least two (2) of said testing channels have no LAL reactive substance therein; and at least two (2) of said testing channels have a spike with an amount of a LAL reactive-substance isolated therein. 
     
     
       4. The microfluidic cartridge of  claim 1 , wherein all of said testing channels have at least one additional reagent isolated therein, said additional reagent comprising a detection reagent. 
     
     
       5. The microfluidic cartridge of  claim 1  further comprising an exit port in fluid communication with said inlet port for removing excess of said fluid sample. 
     
     
       6. The microfluidic cartridge of  claim 1 , wherein said valve is configured to allow vacuum, centrifugal forces, or pneumatic pressure to motivate said aliquot to flow across said valve from said metering portion to said analyzing portion. 
     
     
       7. The microfluidic cartridge of  claim 1  further comprising a first pressure port positioned within said metering portion and adjacent to an end of said analyzing portion for creating a pressure differential within said testing channel. 
     
     
       8. The microfluidic cartridge of  claim 7  further comprising a second pressure port positioned within said mixing portion for creating a pressure differential within said testing channel. 
     
     
       9. The microfluidic cartridge of  claim 1 , wherein said analyzing portion includes an optical chamber to receive at least a portion of said aliquot for optical measurement of said fluid sample. 
     
     
       10. The microfluidic cartridge of  claim 1 , wherein said mixing portion is configured to allow said aliquot to mix with said reagent within said mixing portion. 
     
     
       11. The microfluidic cartridge of  claim 1 , wherein said reagent is immobilized within said mixing portion. 
     
     
       12. The microfluidic cartridge of  claim 1 , wherein said analyzing portion is positioned between said metering portion and said mixing portion;
 wherein a volume of said mixing portion is greater than a volume of said metering portion. 
 
     
     
       13. A method for testing at least one fluid sample for  Limulus amebocyte lysate  (LAL)-reactive substances, said method comprising:
 using a microfluidic cartridge, said microfluidic cartridge comprising at least two (2) testing modules, wherein:
 each testing module includes at least one inlet port for receiving one of said fluid samples, and at least four (4) testing channels in fluid communication with said inlet port; and 
 each of said testing channels includes a metering portion for metering an aliquot of said fluid sample, an analyzing portion, and a mixing portion, said metering portion fluidly communicates with said analyzing portion, and said analyzing portion fluidly communicates with said mixing portion, 
 wherein a valve is positioned between said metering portion and said analyzing portion to selectively fluidly separate said metering portion from said analyzing portion; 
 wherein said microfluidic cartridge contains a reagent for detecting said LAL-reactive substances; 
 
 introducing said at least one fluid sample into at least one of said inlet ports; 
 performing a testing process for said LAL-reactive substances on each of said at least one fluid sample in said microfluidic cartridge; and 
 recording measurement data from said testing process. 
 
     
     
       14. The method of  claim 13  further comprising motivating flow of each of said aliquots from said metering portions to said analyzing portions for optical measurement in said analyzing portion of each testing channel. 
     
     
       15. The method of  claim 14 , wherein a vacuum, centrifugal forces, or pneumatic pressure motivates flow of said aliquot across said valve from said metering portion to said analyzing portion. 
     
     
       16. The method of  claim 15 , wherein each of said testing modules includes at least one pressure port to which said vacuum or pneumatic pressure is applied to create a pressure differential within said testing modules to motivate flow of said aliquots. 
     
     
       17. The method of  claim 13 , wherein introducing said at least one fluid sample into at least one of said inlet ports includes manually introducing said at least one fluid sample or introducing said at least one fluid sample in an automated manner. 
     
     
       18. The method of  claim 13  further comprising the step of introducing said microfluidic cartridge into an optical reader before introducing said at least one sample fluid into one of said inlet ports. 
     
     
       19. The method of  claim 13 , wherein said fluid sample is mixed with said reagent during said testing process. 
     
     
       20. The method of  claim 13 , wherein said reagent is immobilized within said mixing portion. 
     
     
       21. The method of  claim 13 , wherein said measurement data comprises, aliquot volumes, reaction kinetics, fluid motions, transmission, absorption, optical density, color, color value, hue, spectrum, turbidity, scattered light, chemiluminescence, fluorescence, and magnetic resonance. 
     
     
       22. The method of  claim 21 , wherein said testing process and measurement data are validated using historical measurement data and/or data from known reaction kinetics. 
     
     
       23. The method of  claim 22 , wherein a tracer is immobilized within said mixing portion and/or said analyzing portion to aid in measuring and validating said fluid motions and/or said aliquot volume. 
     
     
       24. The method of  claim 13 , wherein said analyzing portion is positioned between said metering portion and said mixing portion;
 wherein a volume of said mixing portion is greater than a volume of said metering portion.